The surely could have spent a day doing open air smaller detonations, but this thing should not be blown up a ton at a time, I think it has the explosive power about 50 times that of TNT. Sure they could have taken 100 lbs barrel and blow each separately and consecutively over a large area in that desert. I think the issue is that the lack of paying attention by the leadership to details, failed to get an appropriate order to the soldiers in the field to handle these one way or another, and was part of the "laissez faire" attitude of Rumsfeld (indicated by his remarks about looting during the end phase of the war), without thoughts as to who could put their hands on that if not destroyed or kept under lock. Wars are awash with snafus, that was a big one, and someone in the echelon should pay the price for that failure. Where does the buck stop?
